I have been nursing my Dodge truck for the last couple of months, trying to keep it in operation despite a coolant leak that was going through about 1/2-gallon every 500 miles. It was an insidious thing, because no evidence of coolant was appearing in my oil analyses, and I couldn't find a coolant leak under the truck when I stopped, and I never smelled coolant when driving. I finally took the truck to my local trusted mechanic, and he isolated the leak coming at the back of the engine, coming out between the block and head. The leak was hard to find because it was at the very rear of the engine, and the coolant was weeping down the back of the block, and around the clutch housing, finally dripping off at the very bottom. I could drive all day, then stop, and only a few drops of coolant would reach the ground, making a spot about the size of a 50-cent piece. Most of the coolant was being blown off the bottom of the clutch housing and out from under the truck as it travelled down the highway.

I drove the truck for a couple more weeks, but it was inevitable that the head had to come off. I took the truck into the shop on Monday this week, and I heard from them today that the cylinder head is cracked in multiple places. Doing some searching on the net, I find that cylinder head cracking is pretty common on the B engine. So, what to do?

a. Put the engine back together with the cracked head. Hey, it was running fine when I didn't know it had cracks, and maybe they won't progress any farther. I asked my mechanic to send me pictures of the cracks so I could decide whether or not they were in critical areas. He hasn't sent any pictures yet, and that may be unrealistic, as it probably isn't easy to get good pictures of Magnaflux indications.b. Get a reconditioned head and put it on. If it's a recon head, obviously it has some miles on it, but has passed a crack test. But that is no assurance that it won't crack soon after it is put into service on my truck. c. Get a new head and put it on. There are aftermarket heads available that claim to have fixed the problem areas where cracks occur, but what quality level are they? I would prefer a genuine Cummins head. A new head is more expensive, and may be extravagant to put on a shortblock with 448k miles, and in a truck that is worth ~$4000.

What knowledge, experience, and otherwise useful thoughts can the BITOG community offer?

a. NO! It can only get worse and you're into as much labor reinstalling the original head as you would be having a new/repaired/rebuilt one installed.b. Have the cracks in the original head welded and ground smooth if this is an option.c. Maybe, how many $$?

That this thing has done this well over 450K is a tribute to the design and build quality of what was a fairly cheap engine as Cummins engines go.

With as many 24v Dodge/Cummins trucks as they made, you should be able to find a perfectly serviceable head at a junkyard for way cheaper than $1800.

And I'm not sure where you picked up that 24v head cracks are common--that's just not even remotely true. Does it happen? Sure. Common? Absolutely not. The only ones I've ever heard of were on engines that were severely abused. Think engines with aftermarket injectors, bigger turbos, exhaust temps frequently exceeding 1400+ degrees and boost pressures at 40+ psi.

If it were me, if the head couldn't be repaired I'd look for a good used one with valves and valve springs in good shape. That shouldn't cost you an arm and a leg and should give you many more years of reliable service.

I am not afraid of a used/recon head that passes a magnaflux, Cracks in B-Series heads are quite common with as many heat cycles as yours has seen. Most don't extend out of the combustion area or for that matter....Beyond between the valve seats/injector hole. But it would suck to drop a valve seat or have one of the cracks extend once the head is torqued down.

Many of the B blocks from that era are the dreaded "53" block, which crack & leak antifreeze down below the freeze plugs long before the head. One of those would be a good head donor. There's a car-part.com junkyard in MI I saw with a wrecked truck that only wants $1000 for a 129K mile engine, that would be the way I'd go, esp. if I could get a warranty (of any length) with it.

And I'm not sure where you picked up that 24v head cracks are common--that's just not even remotely true. Does it happen? Sure. Common? Absolutely not.

To be honest....There aren't many unmodified ISB Dodge trucks. And on the medium duty side.....It's quite common if you actually "Flux" the head.

Nah, there are way more unmodified ISB trucks than modified. Those of us who modify them tend to associate with others who modify them, so after a period of time the majority of trucks we're familiar with are the modified ones. Keep in mind that Dodge put out huge numbers of these trucks with the Cummins. The average guy bought one (or leased it) and dumped it within 5 years. The next guy did the same thing, and the majority ended up in a junkyard completely stock. If you're talking about the few remaining 1998.5-2002 24v (Dodge application) engines on the road *today* then I would probably agree with you that most of those trucks are modified to some degree. That could be anything from an ancient Edge EZ and a set of 275 HP RV injectors to pretty much anything.

I'll take your word for it on smallish cracks revealed by fluxing the head. It sounds like you've got a lot more experience than I do tearing these engines down. I was thinking solely of cracks large enough to result in coolant or boost leaks. Small ones like you're talking about just didn't occur to me.

Looks like a new OEM head is about $1,800 to $2,200? Plus labor? That seems like the way to go.

Are you planning on keeping the truck? 450k on one of those really isn't that bad, unless Michigan has taken it's toll on the rest of the truck.

That being said, can you find another clean 24v Cummins for $3k? I doubt it... maybe a beat up one that you have no idea the history of.

My truck is still in good condition. The chassis is clean and rust-free, and the body only has one rust hole forming in the left side wheel arch. I have kept up the maintenance on it through the years and know everything, good and bad, that has happened to the truck since 46,000 miles. I was hoping to get to 600k before having to do anything serious with the engine. I talk to RV transporters regularly that have 800k+ on their trucks, and the engines have never been opened. I bet most of them have valve bridge and injector hole cracks, too.

Many of the B blocks from that era are the dreaded "53" block, which crack & leak antifreeze down below the freeze plugs long before the head. One of those would be a good head donor. There's a car-part.com junkyard in MI I saw with a wrecked truck that only wants $1000 for a 129K mile engine, that would be the way I'd go, esp. if I could get a warranty (of any length) with it.

This could be good. That website is showing two trucks within 70 miles of me that have ~140k miles on them. No prices listed, though, have to call them. And the website says extended warranties are extra cost. This option has the risk element because there is no way of knowing how much abuse the engine has had, and I wouldn't know what condition the head is in until I get it off the engine and have it inspected. "You pays your money, and you takes your chances."